643112461 has 2 divisors, whose sum is σ = 643112462. Its totient is φ = 643112460.

The previous prime is 643112419. The next prime is 643112521. The reversal of 643112461 is 164211346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 556063561 + 87048900 = 23581^2 + 9330^2 .

It is a cyclic number.

It is not a de Polignac number, because 643112461 - 2⁷ = 643112333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643115461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321556230 + 321556231.

It is an arithmetic number, because the mean of its divisors is an integer number (321556231).

Almost surely, 2^643112461 is an apocalyptic number.

It is an amenable number.

643112461 is a deficient number, since it is larger than the sum of its proper divisors (1).

643112461 is an equidigital number, since it uses as much as digits as its factorization.

643112461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 28.

The square root of 643112461 is about 25359.6620837108. The cubic root of 643112461 is about 863.1686162135.

The spelling of 643112461 in words is "six hundred forty-three million, one hundred twelve thousand, four hundred sixty-one".